The present invention relates to roller shutters, such as applied to window or doorway wall openings, to control the passage of air and light, as well as persons and objects, through the wall opening.
More particularly, the invention relates to roller shutters of the type which include a plurality of elongate slats coupled together to form a slat assembly, and a winding device, e.g., a rotatable drum, overlying the slat assembly for winding and unwinding the slat assembly to a fully-closed position, a fully-open position, and a partially-open position, with respect to the wall opening. In such roller shutters, it is desirable to couple the slats together by couplings which permit the slats, when the slat assembly is in a fully-opened or partially-opened position with respect to the wall opening, to move; a) linearly away from its adjacent slats in the slat assembly to create light and air spaces between adjacent slats; b) linearly towards its adjacent slats in the slat assembly to close or restrict the light and air spaces, and c) angularly with respect to its adjacent slats in the slat assembly to enable the slat assembly to be wound onto or unwound from the winding device.
Many different roller shutter constructions have been proposed and described in the patent literature to enable the slat assembly to serve the foregoing functions. Most of the prior designs include various constructions of elongate linking slats, or elongate linking extensions to the shutter slats in the slat assembly, which linking slats or extensions extend for the length of, and between, the shutter slats and are formed with openings to be opened or closed by the linear movements of the shutter slats with respect to each other. However, such construction, including linking slats or linking extensions to the shutter slats, limit the sizes of the light and air spaces which can be opened by the linear movements of the slats. Moreover, such linking slats and linking extensions may jam or otherwise interfere with the winding and unwinding of the slat assembly. Further, they require a significant amounts of additional slat material, thereby increasing the cost of producing such slats as well as the weight of the completed shutter.
Another construction recently appearing on the market utilizes pivotal joints pivotally and slidably coupling the slats with each other to permit each slat to move linearly by a slideable action, and angularly by a pivotal action, with respect to its adjacent slats. However, such pivotal joints constrain the relative movements of the slats to pivotal and slideable movements. Such pivotal and slidable movements of solid surfaces with respect to each other increase the possibility of jamming during an operation of the shutter, increase friction between the relatively moveable parts and therefore wear and tear, and also require low-friction materials to minimize the friction and wear and tear. Such shutters are also relatively expensive to produce and assemble, and to disassemble for repair or replacement of slats.
An object of the present invention is to provide a rotatable shutter having advantages in one or more of the above respects.
The present invention relates to a roller shutter for a window or doorway wall opening, comprising: a plurality of elongate slats coupled together to form a slat assembly; and a winding device overlying the slat assembly for winding or unwinding the slat assembly to a fully-closed position, a fully-opened position, and a partially-opened position, with respect to the wall opening; the slats being coupled together by couplings which permit each slat, when in a fully-opened or partially-opened position with respect to the wall opening, to move: (a) linearly away from an adjacent slat in the slat assembly to create a light and air space between the adjacent slats; (b) linearly towards the adjacent slat in the slat assembly to close or restrict the light and air spaces; and (c) angularly with respect to the adjacent slat in the slat assembly to enable the slat assembly to be wound onto or unwound from the winding device.
The present invention is characterized in that the couplings are flexible links coupling each side of each slat to the respective side of the adjacent slat.
According to the preferred embodiment of the invention described below, the flexible links may be in the form of short lengths of flexible wires or fibers, or flexible plastic strips, coupled at their ends to the sides of adjacent slats.
According to further features, each of the attachments comprise: a base attached to the side of the slat; and a pair of arms integrally formed with the base such that the arms project laterally from the respective side of the slat with one arm overlying the other. Each of the flexible links couples the overlying arm of one slat with the underlying arm of the adjacent overlying slat. In the described preferred embodiment, each of the arms is formed with a hole for receiving the respective flexible link, and each of the flexible links is formed with an enlarged head at each end blocking the pull-out of the flexible link from its respective hole during a normal use of the shutter.
As will be described more particularly below, roller shutters constructed in accordance with the foregoing features permit substantial amounts of light and air spaces to be created between adjacent slats, as compared to the prior art constructions briefly described above including elongate linking slats or linking extensions to the shutter slats. Since the couplings do not involve pivotal or slidable joints, but rather flexible links, they avoid the above-mentioned dangers of jamming, high friction, and high wear and tear involved in the roller shutter including pivotal-slidable joints; and moreover, they are less expensive to produce, assemble and disassemble for repair or slat-replacement purposes.
Further features and advantages of the invention will be apparent from the description below.